辛伐他汀在心肌细胞缺血再灌注中的作用及机制

Effect and Molecular Mechanism of Simvastatin in Myocardial Ischemia and Reperfusion

目的研究辛伐他汀在大鼠乳鼠心肌细胞缺血再灌注损伤中的保护作用及分子机制。方法分离培养乳鼠心肌细胞,建立I/R模型,实验分组:正常对照组(Control组)、缺血再灌注组(I/R组)、辛伐他汀预处理组(Sim,按辛伐他汀浓度分为0.1μmol/L、1.0μmol/L、10.0μmol/L的低、中、高三个浓度组)、辛伐他汀+锌原卟啉(Znpp)组、辛伐他汀+全反视黄酸(ATRA)组。使用流式细胞仪检测心肌细胞凋亡率,检测细胞上清液中CK,LDH的水平变化。运用Western blot分析HO-1、Nrf2的蛋白表达水平。结果与I/R组相比,1.0μmol/L、10.0μmol/L Sim组细胞凋亡率明显下降,LDH、CK平均值明显下降,而HO-1蛋白水平及Nrf2蛋白水平与I/R相比均明显增加。而Znpp会阻断辛伐他汀预处理对心肌细胞的保护作用,ATAR的加入会抑制Nrf2在细胞核的聚集进而抑制辛伐他汀对HO-1的诱导。结论辛伐他汀预处理诱导大鼠乳鼠心肌细胞HO-1过表达,抑制缺氧复氧心肌细胞凋亡,作用机制可能与Nrf2-ARE信号通路相关。

Objective To investigate the protective effect and molecular mechanism of simvastatin in myocardial ischemia and reperfusion.Methods Cardiomyocytes were pretreated with simvastatin before ischemia and reperfusion（I/R） treatment.the groups in this paper were： ①control group,②I/R group,③simvastatin groups,including three different concentration of simvastatin（0.1 μmol/L,1 μmol/L and 10 μmol/L）,④Simvastatin＋Znpp group,⑤Simvastatin＋ARTA group.The cardiacmyocyte apoptosis ratio was detected by V/PI with flow cytometry.The levels of LDH and CK in cell supernatants were measured.HO-1 and Nrf2 protein expressions were analyzed by Western blot.Results The cardiacmyocyte apoptosis ratios,Levels of CK and LDH in 1 μmol/l,10 μmol/L simvastatin groups were lower than that in the I/R group.The level of HO-1,Nrf2 protein expression increased significantly.Znpp will abolish the protective effect of pretreatment with simvastatin.Besides,ATRA will block the accumulation of Nrf2 in nucleus and decrease HO-1 protein expression which would be induced by pretreatment with simvastatin.Conclusion Simvastatin can induce over expression of HO-1,and decrease the cardiacmyocyte apoptosis ratio in I/R.The mechanism is related to Nrf2-ARE signaling pathway.